Watch water resistance

Salt water in particular can be harmful to watches. The label “Water Resistant” does not automatically mean that a watch is fully waterproof. If only “Water Resistant” appears on the dial or case back, you can generally assume the watch is 3 ATM. If there is no indication of water resistance at all, the watch is likely not splash-proof.

Below you will find an overview to better understand the level of water resistance of your watch. Water resistance can sometimes be confusing, but it is an important feature.

What does ATM on a watch mean?

You may wonder why a watch states “30 metres” while you are not able to swim with it. This relates to the meaning of ATM (Atmospheres) and bar, which indicate how much pressure per square metre the watch can withstand. Manufacturers test watches under controlled conditions. In practice, water pressure increases when you move your arm while swimming or diving.

From 10 ATM (100 metres) and higher, a watch is generally suitable for swimming.

It is also important to know that the rubber gasket inside the case can be damaged when the watch is opened, for example during a battery replacement. A watch with a snap back may therefore lose some of its water resistance. A screw-back case retains water resistance better, provided the gasket is replaced correctly.

Watch with condensation

Condensation inside a watch is not always a bad sign. It can occur when the glass cools quickly while the case is still warm from body temperature. In most cases the condensation will disappear after some time.

If large water droplets are visible inside the watch, leakage may have occurred. This is often visible near the edge of the glass. In that case, we recommend having the watch checked to prevent damage to the movement.

Tips to maintain water resistance

• Avoid contact with chemicals such as hairspray, perfume, chlorine and alcohol.
• Avoid exposure to heat from hot water, prolonged sunlight or a hairdryer.
• After contact with salt water, rinse the watch with fresh water and dry it carefully with a soft cloth.
• Check that the watch glass is not deeply scratched.

Water resistance overview